TABLE 11-1
Psychologists have found that people are generally reluctant to transmit bad news to their peers. This phenomenon has been termed the "MUM effect." To investigate the cause of the MUM effect, 40 undergraduates at Duke University participated in an experiment. Each subject was asked to administer an IQ test to another student and then provide the test taker with his or her percentile score. Unknown to the subject, the test taker was a bogus student who was working with the researchers. The experimenters manipulated two factors: subject visibility and success of test taker, each at two levels. Subject visibility was either visible or not visible to the test taker. Success of the test taker was either top 20% or bottom 20%. Ten subjects were randomly assigned to each of the 2 x 2 = 4 experimental conditions, then the time (in seconds) between the end of the test and the delivery of the percentile score from the subject to the test taker was measured. (This variable is called the latency to feedback.) The data were subjected to appropriate analyses with the following results.

-Referring to Table 11-1, what type of experimental design was employed in this study?
A) completely randomized design with 4 treatments
B) randomized block design with four treatments and 10 blocks
C) 2 x 2 factorial design with 10 replications
D) None of the above.

Question

TABLE 11-1
Psychologists have found that people are generally reluctant to transmit bad news to their peers. This phenomenon has been termed the "MUM effect." To investigate the cause of the MUM effect, 40 undergraduates at Duke University participated in an experiment. Each subject was asked to administer an IQ test to another student and then provide the test taker with his or her percentile score. Unknown to the subject, the test taker was a bogus student who was working with the researchers. The experimenters manipulated two factors: subject visibility and success of test taker, each at two levels. Subject visibility was either visible or not visible to the test taker. Success of the test taker was either top 20% or bottom 20%. Ten subjects were randomly assigned to each of the 2 x 2 = 4 experimental conditions, then the time (in seconds) between the end of the test and the delivery of the percentile score from the subject to the test taker was measured. (This variable is called the latency to feedback.) The data were subjected to appropriate analyses with the following results.
 
-Referring to Table 11-1, what type of experimental design was employed in this study?
A) completely randomized design with 4 treatments 
B) randomized block design with four treatments and 10 blocks 
C) 2 x 2 factorial design with 10 replications 
D) None of the above.

Quizplus · Accepted Answer

The experiment employed a 2 x 2 factorial design with 10 replications. This means that there were four treatment conditions (subject visibility and success of test taker), each with two levels, and each condition was repeated 10 times (with 10 subjects randomly assigned to each condition). This design allows for the testing of both main effects and interactions between the two factors.

TABLE 11-1 Psychologists Have Found That People Are Generally Reluctant to Transmit